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Ryzen Threadripper PRO 3955WX - AMD
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Ryzen Threadripper PRO 3955WX
General Info
ManufacturerTSMC, GlobalFoundries
Model NumberPRO 3955WX
Part Number100-000000167,
IntroductionJuly 14, 2020 (launched)
General Specs
FamilyRyzen Threadripper
Frequency3,900 MHz
Turbo Frequency4,300 MHz
Clock multiplier39
ISAx86-64 (x86)
MicroarchitectureZen 2
Core NameCastle Peak
Core Family23
Core Model49
Core SteppingB0
Process7 nm, 12 nm
MCPYes (3 dies)
Word Size64 bit
Max Memory2 TiB
Max SMP1-Way (Uniprocessor)
TDP280 W
TDP (Typical)233 W
Tjunction0 °C – 90 °C
PackagesWRX8, FCLGA-4094 (FC-OLGA)
Dimension75.4 mm × 58.5 mm × 6.26 mm
Pitch0.87 mm × 1 mm

Ryzen Threadripper PRO 3955WX is a 64-bit 16-core high performance x86 workstation microprocessor introduced by AMD in mid-2020. This multi-chip processor, which is based on their Zen 2 microarchitecture, incorporates two Core Complex Dies fabricated on a TSMC 7 nm process and an I/O die fabricated on a GlobalFoundries 12 nm process. The PRO 3955WX has a TDP of 280 W with a base frequency of 3.9 GHz and a boost frequency of up to 4.3 GHz. This processor supports up to 2 TiB of octa-channel DDR4-3200 memory.


Main article: Zen 2 § Cache

[Edit/Modify Cache Info]

hierarchy icon.svg
Cache Organization
Cache is a hardware component containing a relatively small and extremely fast memory designed to speed up the performance of a CPU by preparing ahead of time the data it needs to read from a relatively slower medium such as main memory.

The organization and amount of cache can have a large impact on the performance, power consumption, die size, and consequently cost of the IC.

Cache is specified by its size, number of sets, associativity, block size, sub-block size, and fetch and write-back policies.

Note: All units are in kibibytes and mebibytes.
L1$1 MiB
1,024 KiB
1,048,576 B
L1I$512 KiB
524,288 B
0.5 MiB
16 × 32 KiB8-way set associative 
L1D$512 KiB
524,288 B
0.5 MiB
16 × 32 KiB8-way set associativewrite-back

L2$8 MiB
8,192 KiB
8,388,608 B
0.00781 GiB
  16 × 512 KiB8-way set associativewrite-back

L3$64 MiB
65,536 KiB
67,108,864 B
0.0625 GiB
  4 × 16 MiB16-way set associativewrite-back

Memory controller

This processor supports UDIMM, RDIMM, LRDIMM, and 3DS RDIMM memory. The maximum memory capacity is 2 TiB using eight 256 GiB LRDIMMs or 3DS RDIMMs.

[Edit/Modify Memory Info]

ram icons.svg
Integrated Memory Controller
Max TypeDDR4-3200
Supports ECCYes
Max Mem2 TiB
Max Bandwidth204.8 GB/s
117.701 GiB/s
120,525.977 MiB/s
0.115 TiB/s
0.126 TB/s
Single 25.6 GB/s
Double 51.2 GB/s
Quad 102.4 GB/s
Octa 204.8 GB/s


Main article: Castle Peak § I/O Interfaces

[Edit/Modify Expansions Info]

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Expansion Options
PCIeRevision: 4.0
Max Lanes: 128
Configuration: x16, x8, x4, x2, x1
SATARevision: 3.2
Max Ports: 32
USBRevision: 3.2 Gen 2×1
Max Ports: 4
Rate: 10 Gbit/s


This processor has no integrated graphics.


[Edit/Modify Supported Features]

Supported x86 Extensions & Processor Features
MMXMMX Extension
EMMXExtended MMX Extension
SSEStreaming SIMD Extensions
SSE2Streaming SIMD Extensions 2
SSE3Streaming SIMD Extensions 3
SSSE3Supplemental SSE3
SSE4.1Streaming SIMD Extensions 4.1
SSE4.2Streaming SIMD Extensions 4.2
SSE4aStreaming SIMD Extensions 4a
AVXAdvanced Vector Extensions
AVX2Advanced Vector Extensions 2
ABMAdvanced Bit Manipulation
BMI1Bit Manipulation Instruction Set 1
BMI2Bit Manipulation Instruction Set 2
FMA33-Operand Fused-Multiply-Add
AESAES Encryption Instructions
RdRandHardware RNG
SHASHA Extensions
ADXMulti-Precision Add-Carry
CLMULCarry-less Multiplication Extension
F16C16-bit Floating Point Conversion
x86-1616-bit x86
x86-3232-bit x86
x86-6464-bit x86
RealReal Mode
ProtectedProtected Mode
SMMSystem Management Mode
FPUIntegrated x87 FPU
SMTSimultaneous Multithreading
AMD-ViAMD-Vi (I/O MMU virtualization)
AMD-VAMD Virtualization
TSMETransparent SME
SenseMISenseMI Technology


Has subobject
"Has subobject" is a predefined property representing a container construct and is provided by Semantic MediaWiki.
Ryzen Threadripper PRO 3955WX - AMD#pcie +
base frequency3,900 MHz (3.9 GHz, 3,900,000 kHz) +
chipsetWRX80 +
clock multiplier39 +
core count16 +
core family23 +
core model49 +
core nameCastle Peak +
core steppingB0 +
cpuid0x00830F10 +
designerAMD +
die count3 +
familyRyzen Threadripper +
first launchedJuly 14, 2020 +
full page nameamd/ryzen threadripper/pro 3955wx +
has advanced vector extensionstrue +
has advanced vector extensions 2true +
has amd amd-v technologytrue +
has amd amd-vi technologytrue +
has amd sensemi technologytrue +
has amd transparent secure memory encryption technologytrue +
has ecc memory supporttrue +
has featureAdvanced Vector Extensions +, Advanced Vector Extensions 2 +, Advanced Encryption Standard Instruction Set Extension + and SenseMI Technology +
has locked clock multipliertrue +
has simultaneous multithreadingtrue +
has x86 advanced encryption standard instruction set extensiontrue +
instance ofmicroprocessor +
is multi-chip packagetrue +
isax86-64 +
isa familyx86 +
l1$ size1,024 KiB (1,048,576 B, 1 MiB) +
l1d$ description8-way set associative +
l1d$ size512 KiB (524,288 B, 0.5 MiB) +
l1i$ description8-way set associative +
l1i$ size512 KiB (524,288 B, 0.5 MiB) +
l2$ description8-way set associative +
l2$ size8 MiB (8,192 KiB, 8,388,608 B, 0.00781 GiB) +
l3$ description16-way set associative +
l3$ size64 MiB (65,536 KiB, 67,108,864 B, 0.0625 GiB) +
ldateJuly 14, 2020 +
manufacturerTSMC + and GlobalFoundries +
market segmentWorkstation +
max cpu count1 +
max junction temperature363.15 K (90 °C, 194 °F, 653.67 °R) +
max memory2,097,152 MiB (2,147,483,648 KiB, 2,199,023,255,552 B, 2,048 GiB, 2 TiB) +
max memory bandwidth117.701 GiB/s (204.8 GB/s, 120,525.977 MiB/s, 0.115 TiB/s, 0.126 TB/s) +
max memory channels8 +
max sata ports32 +
max usb ports4 +
microarchitectureZen 2 +
min junction temperature273.15 K (0 °C, 32 °F, 491.67 °R) +
model numberPRO 3955WX +
nameRyzen Threadripper PRO 3955WX +
packagesWRX8 + and FCLGA-4094 +
part number100-000000167 + and 100-100000167WOF +
process7 nm (0.007 μm, 7.0e-6 mm) + and 12 nm (0.012 μm, 1.2e-5 mm) +
series3900 +
smp max ways1 +
socketsWRX8 +
supported memory typeDDR4-3200 +
tdp280 W (280,000 mW, 0.375 hp, 0.28 kW) +
tdp (typical)233 W (233,000 mW, 0.312 hp, 0.233 kW) +
technologyCMOS +
thread count32 +
transistor count15,940,000,000 +
turbo frequency4,300 MHz (4.3 GHz, 4,300,000 kHz) +
word size64 bit (8 octets, 16 nibbles) +